CN104767454A - Control method for lowering non-bearing flux switching motor rotor suspension current - Google Patents

Abstract

The invention provides a control method for lowering non-bearing flux switching motor rotor suspension current. A rotor suspension current peak value is further lowered, and rotor suspension operation stability is improved. The method comprises the steps of suspension current generating, and a corresponding motor suspension winding structure is included. A motor can be of a double-winding structure or a single-winding structure, for the double-winding structure, current flows to a suspension winding, suspension force is generated, and for the single-winding structure, suspension current and torque current flow to the winding at the same time. Suspension current flows to the two-phase suspension winding with vertical mechanical space, two suspension forces with spaces approximately vertical are generated, and the two suspension forces are used for being combined into the suspension force needed for a rotor. Suspension windings work near the position where largest suspension force is generated, and accordingly the suspension current amplitude value is lowered effectively.

Description

A kind of control method reducing bearing-free flux switch motor rotor suspension electric current

Technical field

The present invention relates to a kind of motor control method, particularly a kind of control method reducing bearing-free flux switch motor rotor suspension electric current.

Background technology

Stator permanent magnetic type magnetic flux switches synchronous machine and embeds in stator core by excitatory permanent magnet, is more convenient for distributing of permanent magnet heat; Solve this kind of electromotor no axis and hold technical problem, this kind of motor effectively can be expanded to high speed, Large Copacity, the field such as pollution-free.

The rotor suspension power of stator permanent magnetic type bearingless synchronous motor can adopt six phase windings jointly to produce, and each phase winding flows through the suspending power that electric current produces, outside the Pass having with size of current, also relevant with rotor-position.If flow through larger levitating current in winding, meeting generation current spike, affects rotor suspension traveling comfort.

Stator permanent magnetic type bearingless synchronous motor rotor suspension control method in prior art, adopt six mutually star-like simplex winding structures, two phase windings of mechanical space symmetry are utilized to flow through levitating current, break the balance in magnetic field in the symmetrical air gap of electromechanics, thus the rotor suspension power required for producing, levitating current dependent controls.Obviously, any instantaneous six phase winding current-sharing overcurrent, rotor suspension power is produced jointly by six phase windings.Each phase winding flows through the suspending power coefficient that unit positive current produces, relevant with rotor-position.When certain phase winding suspending power coefficient close to zero time, if still require, this exports certain suspending power mutually, then must flow through larger levitating current in this phase winding, thus create current spike.Excessive peak current is unallowed for the motor of finite electric current capacity, and limited inverter power tube current capacity also limit and flows through current spike value in winding.

Summary of the invention

For solving the levitating current spike difficult problem occurred in existing levitating current dependent control method, the stability that when improving stator permanent magnetic type synchronous machine mechanical bearings further, rotor suspension controls.The present invention proposes a kind of control method reducing bearing-free flux switch motor rotor suspension electric current.

The present invention realizes by the following technical solutions: a kind of control method reducing bearing-free flux switch motor rotor suspension electric current, one stator permanent magnet type non-bearing motor is provided, it is characterized in that: comprise the following steps: step S01: suspending power coefficients calculation block is provided, sector judges link, current controller and the given calculating link of levitating current; Step S02: by described electrical angle of motor rotor θ _rgive described suspending power coefficients calculation block, calculated the suspending power coefficient of each winding of described motor by described suspending power coefficients calculation block; Step S03: by described electrical angle of motor rotor θ _rgive described sector and judge link, described sector judges that link exports sector number; Step S04: by given for x-axis suspending power y-axis suspending power is given suspending power coefficient and sector number give levitating current given calculating link simultaneously, export each winding levitating current set-point by described levitating current given calculating link simultaneously; Step S05: realize actual levitating current by described current controller and follow the tracks of respective set-point, to produce the suspending power required for rotor suspension.

In an embodiment of the present invention, described motor is double-winding motor; It comprises a1, a2, b1, b2, c1, c2 winding.

In an embodiment of the present invention, described motor is simplex winding motor, comprises a1, a2, a3, a4, b1, b2, b3, b4, c1, c2, c3, c4 winding.

Further, step S02 also comprises following concrete steps: step S021: utilize finite element method or experimental technique first to obtain a1 winding suspending power coefficient F that rotor-position is in each point place within the scope of 0 ° ~ 36 ° mechanical angles _xa1a3, F _ya1a3; Step S022: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+18 places _xa1a3(18+ θ _m), F _ya1a3(18+ θ _m), calculate a2 winding suspending power coefficient F according to electromechanics design feature _xa2a4, F _ya2a4as follows: $\left[\begin{array}{c}{F}_{\mathrm{xa}2a4}\\ F_{\mathrm{ya}2a4}\end{array}\right]=\left[\begin{array}{cc}0& 1\\ -1& 0\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xala}3}(18+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(18+{\mathrm{\θ}}_m)\end{array}\right];$ Step S023: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+12 places _xa1a3(12+ θ _m), F _ya1a3(12+ θ _m), calculate b1 winding suspending power coefficient F according to electromechanics design feature _xb1b3, F _yb1b3as follows: $\left[\begin{array}{c}{F}_{\mathrm{xb}1b3}\\ F_{\mathrm{yb}1b3}\end{array}\right]=\left[\begin{array}{cc}\cos 60& -\sin 60\\ \sin 60& \cos 60\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(12+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(12+{\mathrm{\θ}}_m)\end{array}\right];$ Step S024: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+30 places _xa1a3(30+ θ _m), F _ya1a3(30+ θ _m); B2 winding suspending power coefficient F is calculated according to electromechanics design feature _xb2b4, F _yb2b4as follows: $\left[\begin{array}{c}{F}_{\mathrm{xb}2b4}\\ F_{\mathrm{yb}2b4}\end{array}\right]=\left[\begin{array}{cc}\sin 60& \cos 60\\ -\cos 60& \sin 60\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(30+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(30+{\mathrm{\θ}}_m)\end{array}\right];$ Step S025: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+6 places _xa1a3(6+ θ _m), F _ya1a3(6+ θ _m); C1 winding suspending power coefficient F is calculated according to electromechanics design feature _xc1c3, F _yc1c3as follows: $\left[\begin{array}{c}{F}_{\mathrm{xc}1c3}\\ F_{\mathrm{yc}1c3}\end{array}\right]=\left[\begin{array}{cc}-\cos 30& \sin 30\\ -\sin 30& -\cos 30\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(6+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(6+{\mathrm{\θ}}_m)\end{array}\right];$

Step S026: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+24 places _xa1a3(24+ θ _m), F _ya1a3(24+ θ _m); C2 winding suspending power coefficient F is calculated according to electromechanics design feature _xc2c4, F _yc2c4as follows: $\left[\begin{array}{c}{F}_{\mathrm{xc}2c4}\\ F_{\mathrm{yc}2c4}\end{array}\right]=\left[\begin{array}{cc}-\sin 30& -\cos 30\\ \cos 30& -\sin 30\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(24+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(24+{\mathrm{\θ}}_m)\end{array}\right].$

In an embodiment of the present invention, described step S04 also comprises following lower concrete steps: step S041: work as θ _rbe in (60 °, 120 °) and (240 °, 300 °) interior time, a1 and a2 winding flows through the corresponding levitating current set-point of levitating current and is calculated as follows: $\left[\begin{array}{c}{i}_{a1a3}^{*}\\ i_{a2a4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xa}1a3}& F_{\mathrm{xa}2a4}\\ F_{\mathrm{ya}1a3}& F_{\mathrm{ya}2a4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right];$ Step S042: work as θ _rbe in (120 °, 180 °) and (300 °, 360 °) interior time, b1 and b2 winding flows through levitating current, and corresponding levitating current set-point is calculated as follows: $\left[\begin{array}{c}{i}_{b1b3}^{*}\\ i_{b2b4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xb}1b3}& F_{\mathrm{xb}2b4}\\ F_{\mathrm{yb}1b3}& F_{\mathrm{yb}2b4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right];$ Step S043: work as θ _rbe in (180 °, 240 °) and (0 °, 60 °) interior time, c1 and c2 winding flows through levitating current, and corresponding levitating current set-point is calculated as follows: $\left[\begin{array}{c}{i}_{c1c3}^{*}\\ i_{c2c4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xc}1c3}& F_{\mathrm{xc}2c4}\\ F_{\mathrm{yc}1c3}& F_{\mathrm{yc}2c4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right].$

Further, described x-axis suspending power is given described y-axis suspending power is given export respectively by x-axis displacement controller and y-axis displacement controller.

Further, described x-axis displacement controller and described y-axis displacement controller are PI controller.

In an embodiment of the present invention, described current controller adopts current hysteresis comparator control or PWM current follow-up control.

Adopt technical scheme of the present invention, independently control levitating current, namely each levitating current electrically on contact directly; Any instantaneous two pairs of windings only utilizing mechanical space orthogonal produce two rotor suspension force components of space nearly orthogonal, and utilize them to synthesize the suspending power of any direction and size; Two pairs of orthogonal winding for generation of suspending power only flow through electric current respective generation within the scope of ° electrical degree of maximum suspension force ± 30.Compared with prior art, the present invention has the following advantages:

(1) each suspending windings produces suspending power all near maximum suspending power, greatly improves the utilance of levitating current, effectively reduces levitating current peak value;

(2) for limited stator slot area, because levitating current obtains effective utilization, thus improve the active current for generation of electromagnetic torque, enhance motor belt motor load capacity;

(3) due to effective reduction of levitating current peak value, reduce the current rating of power tube, thus reduce the cost of power inverter, improve drive system reliability of operation and stationarity.

Accompanying drawing explanation

Fig. 1 is motor suspending windings structural representation in one embodiment of the invention.

Fig. 2 is that in one embodiment of the invention, each winding levitating current produces flow chart.

Fig. 3 is in one embodiment of the invention between each suspending windings active region.

Fig. 4 is the three-phase torque winding connection schematic diagram that Fig. 1 is corresponding.

Fig. 5 is the rotor suspension driving system structure schematic diagram that Fig. 1 and Fig. 4 is corresponding.

Fig. 6 is suspending power coefficient calculations flow chart.

Fig. 7 is levitating current given calculating link structural representation.

Fig. 8 is motor winding construction schematic diagram in another embodiment of the present invention.

Fig. 9 is another embodiment of the present invention rotor suspension driving system structure.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention will be further described.

In an embodiment of the present invention, the structural representation of described motor suspending windings as shown in Figure 1.This motor stator has 12 " U " type magnetic conductive iron, the permanent magnets that middle embedding 12 is tangentially alternately magnetized, and magnetizing direction as shown by the arrows in Figure 1.N _sa1, N _sa3suspending windings a1, N in series _sa2, N _sa4suspending windings a2 in series, other suspending windings b1, b2, c1, c2 series system are similar to a1 and a2, and concrete series wiring can see Fig. 1.The winding of orthogonal space is to being respectively: N _sa1, N _sa3with N _sa2, N _sa4, N _sb1, N _sb3with N _sb2, N _sb4, N _sc1, N _sc3with N _sc2, N _sc4.Each winding flows through levitating current and is respectively i _a1a3, i _a2a4, i _b1b3, i _b2b4, i _c1c3, i _c2c4.Xy coordinate system is defined: x-axis and N _sa1, N _sa3dead in line, y-axis and N _sa2, N _sa4dead in line, rotor core groove center line is initially in x-axis.

Each winding levitating current produces flow chart see Fig. 2.First by rotor electrical degree θ _rgive each suspending windings suspending power coefficients calculation block, export a1 winding x-axis and y-axis suspending power coefficient F respectively _xa1a3, F _ya1a3, a2 winding x-axis and y-axis suspending power coefficient F _xa2a4, F _ya2a4, b1 winding x-axis and y-axis suspending power coefficient F _xb1b3, F _yb1b3, b2 winding x-axis and y-axis suspending power coefficient F _xb2b4, F _yb2b4, c1 winding x-axis and y-axis suspending power coefficient F _xc1c3, F _yc1c3, c2 winding x-axis and y-axis suspending power coefficient F _xc2c4, F _yc2c4.Then by rotor electrical degree θ _rgive sector and judge link, export sector number 1,2 or 3.Again by given for x-axis suspending power y-axis suspending power is given suspending power coefficient and sector number give levitating current given calculating link simultaneously, and it is given that levitating current given calculating link exports a1 winding levitating current simultaneously a2 winding levitating current is given b1 winding levitating current is given b2 winding levitating current is given c1 winding levitating current is given c2 winding levitating current is given finally utilize current controller to realize actual levitating current and follow the tracks of respective set-point, to produce the suspending power required for rotor suspension.

After the present invention utilizes and flow through levitating current in two pairs of winding of orthogonal space, the common suspending power producing rotor and need, thus realize rotor suspension.Suspending power is produced for a1 and a2 winding in Fig. 1.After a1 winding flows through unit forward levitating current, the x-axis, the y-axis suspending power that produce correspondence are respectively F _xa1a3, F _ya1a3.Because a1 winding axis is in x-axis, so F _xa1a3much larger than F _ya1a3, ignore F _ya1a3effect, then after can thinking that a1 winding flows through levitating current, the suspending power of generation is approximate is in x-axis direction; Because stator and rotor are salient pole type structure, so F _xa1a3, F _ya1a3all along with rotor position angle θ _rthe sinusoidal rule of basic one-tenth changes and changes.Adopt finite element method, analyze F _xa1a3, F _ya1a3with θ _rvariation relation curve in 0 ~ 360 ° of periodic regime, also can measure this two relation curves by means of the method for experiment.And after analysis a1 winding flows through unit forward levitating current further, produce suspending power and reaching maximum close to rotor-position electrical degree 90 ° and 270 ° of places respectively.In like manner, a2 winding axis is in y-axis, and the suspending power of generation is approximate is in y-axis direction, produces suspending power and is reaching maximum close to rotor-position electrical degree 90 ° and 270 ° of places respectively.In order to reduce a1 and a2 winding levitating current amplitude, each winding should be made full use of and produce suspending power peak value near zone, so get respectively rotor position angle 90 ° and 270 ° ± 30 ° of scopes are as a1 and the a2 zone of action, namely when rotor electric rotating angle is in (60 °, 120 °) and (240 °, 300 °) in scope time, in a1 and a2, flow through suitable levitating current i simultaneously _a1a3, i _a2a4, jointly produce the rotor suspension power met the demands.Same analysis obtains, after b1 and b2 winding flows through levitating current, the suspending power nearly orthogonal produced respectively, the suspending power peak point of respective generation is close to rotor-position electrical degree 150 ° and 330 °, so when rotor electric rotating angle is in (120 °, 180 °) and (300 °, 360 °) scope in time, in b1 and b2, flow through suitable levitating current i simultaneously _b1b3, i _b2b4, jointly produce the rotor suspension power met the demands; After c1 and c2 winding flows through levitating current, the suspending power nearly orthogonal produced respectively, the suspending power peak point of respective generation is close to rotor-position electrical degree 210 ° and 30 °, so when rotor electric rotating angle is in (180 °, 240 °) and (0 °, 60 °) in scope time, in c1 and c2, flow through suitable levitating current i simultaneously _c1c3, i _c2c4, jointly produce the rotor suspension power met the demands.See Fig. 3 between each suspending windings active region.

According to rotor-position electrical degree θ _rand Fig. 3, judge what scope rotor is in, thus unique one group of Working winding can be determined, more just can calculate in Working winding according to given suspending power and flow through levitating current set-point.

The calculation procedure of levitating current set-point is specific as follows:

A () works as θ _rbe in (60 °, 120 °) and (240 °, 300 °) interior time, a1 and a2 winding flows through levitating current, and corresponding levitating current set-point is calculated as follows:

$\left[\begin{array}{c}{i}_{a1a3}^{*}\\ i_{a2a4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xa}1a3}& F_{\mathrm{xa}2a4}\\ F_{\mathrm{ya}1a3}& F_{\mathrm{ya}2a4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right]$ Formula (1);

B () works as θ _rbe in (120 °, 180 °) and (300 °, 360 °) interior time, b1 and b2 winding flows through levitating current, and corresponding levitating current set-point is calculated as follows:

$\left[\begin{array}{c}{i}_{b1b3}^{*}\\ i_{b2b4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xb}1b3}& F_{\mathrm{xb}2b4}\\ F_{\mathrm{yb}1b3}& F_{\mathrm{yb}2b4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right]$ Formula (2);

C () works as θ _rbe in (180 °, 240 °) and (0 °, 60 °) interior time, c1 and c2 winding flows through levitating current, and corresponding levitating current set-point is calculated as follows:

$\left[\begin{array}{c}{i}_{c1c3}^{*}\\ i_{c2c4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xc}1c3}& F_{\mathrm{xc}2c4}\\ F_{\mathrm{yc}1c3}& F_{\mathrm{yc}2c4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right]$ Formula (3).

Wherein, suspending power coefficient F _xa1a3, F _ya1a3for the x that produces when a1 winding flows through unit positive current and y-axis suspending power component; Suspending power coefficient F _xa2a4, F _ya2a4for the x that produces when a2 winding flows through unit positive current and y-axis suspending power component; Suspending power coefficient F _xb1b3, F _yb1b3for the x that produces when b1 winding flows through unit positive current and y-axis suspending power component; Suspending power coefficient F _xb2b4, F _yb2b4for the x that produces when b2 winding flows through unit positive current and y-axis suspending power component; Suspending power coefficient F _xc1c3, F _yc1c3for the x that produces when c1 winding flows through unit positive current and y-axis suspending power component; Suspending power coefficient F _xc2c4, F _yc2c4for the x that produces when c2 winding flows through unit positive current and y-axis suspending power component.

The acquisition of these suspending power coefficients by above-mentioned explanation, can utilize finite element method or experimental technique to obtain successively, also can realize by the following technical solutions:

(1) by above-mentioned explanation, utilize finite element method or experimental technique first to obtain a1 winding suspending power coefficient F that rotor-position is in each point place within the scope of 0 ° ~ 36 ° mechanical angles _xa1a3, F _ya1a3;

(2) according to rotor-position mechanical angle θ _mand step (1), obtain θ _mthe a1 winding suspending power coefficient F at+18 places _xa1a3(18+ θ _m), F _ya1a3(18+ θ _m), then calculate a2 winding suspending power coefficient F according to electromechanics design feature _xa2a4, F _ya2a4as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xa}2a4}\\ F_{\mathrm{ya}2a4}\end{array}\right]=\left[\begin{array}{cc}0& 1\\ -1& 0\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xala}3}(18+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(18+{\mathrm{\θ}}_m)\end{array}\right]$ Formula (4);

(3) according to rotor-position mechanical angle θ _mand step (1), obtain θ _mthe a1 winding suspending power coefficient F at+12 places _xa1a3(12+ θ _m), F _ya1a3(12+ θ _m), then calculate b1 winding suspending power coefficient F according to electromechanics design feature _xb1b3, F _yb1b3as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xb}1b3}\\ F_{\mathrm{yb}1b3}\end{array}\right]=\left[\begin{array}{cc}\cos 60& -\sin 60\\ \sin 60& \cos 60\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(12+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(12+{\mathrm{\θ}}_m)\end{array}\right]$ Formula (5);

(4) according to rotor-position mechanical angle θ _mand step (1), obtain θ _mthe a1 winding suspending power coefficient F at+30 places _xa1a3(30+ θ _m), F _ya1a3(30+ θ _m), then calculate b2 winding suspending power coefficient F according to electromechanics design feature _xb2b4, F _yb2b4as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xb}2b4}\\ F_{\mathrm{yb}2b4}\end{array}\right]=\left[\begin{array}{cc}\sin 60& \cos 60\\ -\cos 60& \sin 60\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(30+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(30+{\mathrm{\θ}}_m)\end{array}\right]$ Formula (6);

(5) according to rotor-position mechanical angle θ _mand step (1), obtain θ _mthe a1 winding suspending power coefficient F at+6 places _xa1a3(6+ θ _m), F _ya1a3(6+ θ _m), then calculate c1 winding suspending power coefficient F according to electromechanics design feature _xc1c3, F _yc1c3as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xc}1c3}\\ F_{\mathrm{yc}1c3}\end{array}\right]=\left[\begin{array}{cc}-\cos 30& \sin 30\\ -\sin 30& -\cos 30\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(6+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(6+{\mathrm{\θ}}_m)\end{array}\right]$ Formula (7);

(6) according to rotor-position mechanical angle θ _mand step (1), obtain θ _mthe a1 winding suspending power coefficient F at+24 places _xa1a3(24+ θ _m), F _ya1a3(24+ θ _m), then calculate c2 winding suspending power coefficient F according to electromechanics design feature _xc2c4, F _yc2c4as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xc}2c4}\\ F_{\mathrm{yc}2c4}\end{array}\right]=\left[\begin{array}{cc}-\sin 30& -\cos 30\\ \cos 30& -\sin 30\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(24+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(24+{\mathrm{\θ}}_m)\end{array}\right]$ Formula (8).

Stator core embeds six suspending windings a1 ~ c2 as shown in Figure 1 and three-phase torque winding a ~ c simultaneously, and as shown in Figure 4, three-phase windings electric current is respectively i to the three-phase torque winding connection of its correspondence _a, i _b, i _c.Provide the concrete connected mode of a phase winding in Fig. 4, b with c is connected, and the rest may be inferred for mode.Corresponding rotor suspension driving system structure as shown in Figure 5.Its rotor rotating operation adopts rotor Rotation Controllers to control.Rotor Rotation Controllers adopts common frequency converter, and control method can adopt common field-oriented vector control or direct torque control.Each suspending windings electric current all adopts a current controller to control actual levitating current and follows the tracks of corresponding set-point.Current controller can adopt current hysteresis comparator control, also can adopt PWM current follow-up control.Adopt x and y direction rotor displacement transducer, measure and obtain the displacement x of rotor in x and y direction and y.Adopt x-axis displacement controller and y-axis displacement controller, export the rotor suspension power set-point in x and y direction respectively preferably, displacement controller adopts PI controller, and other controllers are also passable, as long as it is given to export corresponding suspending power according to offset deviation.Produce link by adopting the levitating current shown in Fig. 2 and export a1 ~ c2 suspending windings given value of current value send to corresponding suspending windings current controller.In Fig. 5, suspending power coefficient calculations flow process as shown in Figure 6.The given calculating link of levitating current adopts structure shown in Fig. 7.Wherein switch S has three positions, is respectively 1 position, 2 positions, 3 positions, and sector judges that the sector number that link exports determines that what position S closes in, and when Working winding is chosen to be a1 and a2, S gets to 1 position; When Working winding is chosen to be b1 and b2, S gets to 2 positions; When Working winding is chosen to be c1 and c2, S gets to 3 positions.

In an alternative embodiment of the invention, described motor is simplex winding motor, and motor stator structure as shown in Figure 8.On stator, 12 coils are a winding separately, are respectively a1, a2, a3, a4, b1, b2, b3, b4, c1, c2, c3, c4, and each winding flows through electric current and is respectively i _a1, i _a2, i _a3, i _a4, i _b1, i _b2, i _b3, i _b4, i _c1, i _c2, i _c3, i _c4.Suspend and tangential rotation to realize rotor radial simultaneously, each winding will flow through levitating current and torque current simultaneously, the suspended coil of Fig. 8 simplex winding structural equivalents on the identical magnetic pole of the stator of Fig. 1 with Fig. 4 and torque coil action effect amalgamation result, in known Fig. 1 and Fig. 4 suspending windings given value of current situation, those skilled in the art easily analyze that to obtain each winding current set-point in Fig. 8 simplex winding structure as follows:

$\begin{array}{c}{i}_{a1}^{*}=i_{a1a3}^{*}+i_a^{*},i_{a2}^{*}=i_{a2a4}^{*}+i_a^{*},i_{b1}^{*}=i_{b1b3}^{*}+i_b^{*},i_{b2}^{*}=i_{b2b4}^{*}+i_b^{*},i_{c1}^{*}=i_{c1c3}^{*}+i_c^{*},i_{c2}^{*}=i_{c2c4}^{*}+i_c^{*}\\ i_{a3}^{*}=i_{a1a3}^{*}-i_a^{*},i_{a4}^{*}=i_{a2a4}^{*}-i_a^{*},i_{b3}^{*}=i_{b1b3}^{*}-i_b^{*},i_{b4}^{*}=i_{b2b4}^{*}-i_b^{*},{i_{c3}^{*}=i}_{c1c3}^{*}-i_c^{*},i_{c4}^{*}=i_{c2c4}^{*}-i_c^{*}\end{array},$ Formula (9).

Fig. 9 is simplex winding rotor suspension driving system structure, and the given calculating link of rotor Rotation Controllers, levitating current, rotor x, y displacement controller, suspending power coefficient calculations link, sector judge that link etc. is see double-winding motor.Difference is that simplex winding motor is by given for levitating current given with three-phase torque winding current give simultaneously and calculate the given link of winding current, export 12 winding currents given each winding adopts an independently current controller, realizes actual winding current and follows the tracks of respective set-point.Current Control part also can see double-winding motor.

Adopt technical scheme of the present invention, independently control levitating current, namely each levitating current electrically on contact directly; Any instantaneous two pairs of windings only utilizing mechanical space orthogonal produce two rotor suspension force components of space nearly orthogonal, and utilize them to synthesize the suspending power of any direction and size; Two pairs of orthogonal winding for generation of suspending power only flow through electric current respective generation within the scope of ° electrical degree of maximum suspension force ± 30.

Those skilled in the art can make various amendment to this specific embodiment or supplement or adopt similar mode to substitute under the prerequisite without prejudice to principle of the present invention and essence, but these changes all fall into protection scope of the present invention.Therefore the technology of the present invention scope is not limited to above-described embodiment.

Claims (8)

1. reduce a control method for bearing-free flux switch motor rotor suspension electric current, it is characterized in that, comprise the following steps:

Step S01: a stator permanent magnet type non-bearing motor, suspending power coefficients calculation block are provided, sector judges the given calculating link of link, current controller and levitating current;

Step S02: by described electrical angle of motor rotor θ _rgive described suspending power coefficients calculation block, calculated the suspending power coefficient of each winding of described motor by described suspending power coefficients calculation block;

Step S03: by described electrical angle of motor rotor θ _rgive described sector and judge link, described sector judges that link exports sector number;

Step S04: by given for x-axis suspending power y-axis suspending power is given suspending power coefficient and sector number give levitating current given calculating link simultaneously, export each winding levitating current set-point by described levitating current given calculating link simultaneously;

Step S05: realize actual levitating current by described current controller and follow the tracks of respective set-point, to produce the suspending power required for rotor suspension.

2. the control method of reduction bearing-free flux switch motor rotor suspension electric current according to claim 1, is characterized in that: described motor is double-winding motor; Described double-winding motor comprises a1, a2, b1, b2, c1, c2 winding.

3. the control method of reduction bearing-free flux switch motor rotor suspension electric current according to claim 1, is characterized in that: described motor is simplex winding motor, comprises a1, a2, a3, a4, b1, b2, b3, b4, c1, c2, c3, c4 winding.

4. the control method of the reduction bearing-free flux switch motor rotor suspension electric current according to Claims 2 or 3, is characterized in that: step S02 also comprises following concrete steps:

Step S021: utilize finite element method or experimental technique first to obtain a1 winding suspending power coefficient F that rotor-position is in each point place within the scope of 0 ° ~ 36 ° mechanical angles _xa1a3, F _ya1a3;

Step S022: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+18 places _xa1a3(18+ θ _m), F _ya1a3(18+ θ _m), calculate a2 winding suspending power coefficient F according to electromechanics design feature _xa2a4, F _ya2a4as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xa}2a4}\\ F_{\mathrm{ya}2a4}\end{array}\right]=\left[\begin{array}{cc}0& 1\\ -1& 0\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(18+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(18+{\mathrm{\θ}}_m)\end{array}\right];$

Step S023: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+12 places _xa1a3(12+ θ _m), F _ya1a3(12+ θ _m), calculate b1 winding suspending power coefficient F according to electromechanics design feature _xb1b3, F _yb1b3as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xb}1b3}\\ F_{\mathrm{yb}1b3}\end{array}\right]=\left[\begin{array}{cc}\cos 60& -\sin 60\\ \sin 60& \cos 60\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(12+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(12+{\mathrm{\θ}}_m)\end{array}\right];$

Step S024: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+30 places _xa1a3(30+ θ _m), F _ya1a3(30+ θ _m); B2 winding suspending power coefficient F is calculated according to electromechanics design feature _xb2b4, F _yb2b4as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xb}2b4}\\ F_{\mathrm{yb}2b4}\end{array}\right]=\left[\begin{array}{cc}\sin 60& \cos 60\\ -\cos 60& \sin 60\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(30+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(30+{\mathrm{\θ}}_m)\end{array}\right];$

Step S025: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+6 places _xa1a3(6+ θ _m), F _ya1a3(6+ θ _m); C1 winding suspending power coefficient F is calculated according to electromechanics design feature _xc1c3, F _yc1c3as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xc}1c3}\\ F_{\mathrm{yc}1c3}\end{array}\right]=\left[\begin{array}{cc}-\cos 30& \sin 30\\ -\sin 30& -\cos 30\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(6+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(6+{\mathrm{\θ}}_m)\end{array}\right];$

Step S026: according to rotor-position mechanical angle θ _m, F _xa1a3and F _ya1a3, obtain θ _mthe a1 winding suspending power coefficient F at+24 places _xa1a3(24+ θ _m), F _ya1a3(24+ θ _m); C2 winding suspending power coefficient F is calculated according to electromechanics design feature _xc2c4, F _yc2c4as follows:

$\left[\begin{array}{c}{F}_{\mathrm{xc}2c4}\\ F_{\mathrm{yc}2c4}\end{array}\right]=\left[\begin{array}{cc}-\sin 30& -\cos 30\\ \cos 30& -\sin 30\end{array}\right]\left[\begin{array}{c}{F}_{\mathrm{xa}1a3}(24+{\mathrm{\θ}}_m)\\ F_{\mathrm{ya}1a3}(24+{\mathrm{\θ}}_m)\end{array}\right].$

5. the control method of the reduction bearing-free flux switch motor rotor suspension electric current according to Claims 2 or 3, is characterized in that: described step S04 also comprises following concrete steps:

Step S041: work as θ _rbe in (60 °, 120 °) and (240 °, 300 °) interior time, a1 and a2 winding flows through the corresponding levitating current set-point of levitating current and is calculated as follows:

$\left[\begin{array}{c}{i}_{a1a3}^{*}\\ i_{a2a4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xa}1a3}& F_{\mathrm{xa}2a4}\\ F_{\mathrm{ya}1a3}& F_{\mathrm{ya}2a4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right];$

Step S042: work as θ _rbe in (120 °, 180 °) and (300 °, 360 °) interior time, b1 and b2 winding flows through levitating current, and corresponding levitating current set-point is calculated as follows:

$\left[\begin{array}{c}{i}_{b1b3}^{*}\\ i_{b2b4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xb}1b3}& F_{\mathrm{xb}2b4}\\ F_{\mathrm{yb}1b3}& F_{\mathrm{yb}2b4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right];$

Step S043: work as θ _rbe in (180 °, 240 °) and (0 °, 60 °) interior time, c1 and c2 winding flows through levitating current, and corresponding levitating current set-point is calculated as follows:

$\left[\begin{array}{c}{i}_{c1c3}^{*}\\ i_{c2c4}^{*}\end{array}\right]={\left[\begin{array}{cc}{F}_{\mathrm{xc}1c3}& F_{\mathrm{xc}2c4}\\ F_{\mathrm{yc}1c3}& F_{\mathrm{yc}2c4}\end{array}\right]}^{-1}\left[\begin{array}{c}{F}_x^{*}\\ F_y^{*}\end{array}\right].$

6. the control method of reduction bearing-free flux switch motor rotor suspension electric current according to claim 1, is characterized in that: described x-axis suspending power is given described y-axis suspending power is given export respectively by x-axis displacement controller and y-axis displacement controller.

7. the control method of reduction bearing-free flux switch motor rotor suspension electric current according to claim 6, is characterized in that: described x-axis displacement controller and described y-axis displacement controller are PI controller.

8. the control method of reduction bearing-free flux switch motor rotor suspension electric current according to claim 1, is characterized in that: described current controller adopts current hysteresis comparator control or PWM current follow-up control.